This invention relates to toilet tank flush valves and more particularly to a flush valve operable for the partial or complete discharge of the tank contents.
Conventional toilet tanks are provided with a bottom drain opening normally closed by a bulbous valve. A lift rod conventionally couples the valve to an operating lever for the elevation of the valve which permits the contents of the tank to discharge. Normally, the closure valve does not become seated in the tank drain opening until all of the contents of the tank have been discharged.
In order to conserve water and power several attempts have been made to minimize the amount of water discharged during each flushing operation. These attempts have normally involved diminishing the water volume in the flushed tank.